Machine for sealing and molding glass bulbs



April 8, 1947. EISL R 2,418,763

MACHINE FOR SEALING AND MOLDING GLASS BULBS Filed Feb. 18, 1944 sSheets-Sheet 1 INVE NT'OR MW y 7 ATI'DR EY April 8,1947. c. EISLER2,418,763

MACHINE FOR SEALING AND MOLDING GLASS BULBS c. EI SLER 2,418,763

MACHINE FOR SEALING AND MOLDING GLASS BULBS April 8, 1947.

Filed Feb. 18, 1944.

3 Sheets-Sheet 3 INVENTOR.

Patented Apr. 8, 1947 MACHINE FOR SEALING AND MOLDING GLASS BULBSCharles Eisler, South Orange, N. J.

Application February 18, 1944, Serial No. 522,942

1 Claim.

This invention relates to an improved machine for sealing and moldingglass bulbs in proper sequence in order to produce a bulb with a neckprepared to receive a screw cap or collar, the collar having spring armswith projections, the neck of the bulb having recesses with which theprojections en age when the two parts are assembled.

The invention is designed to provide a machine in which molds forforming the indented neck of the bulb are resiliently closed fromopposite sides of the bulb while the bulb-is held seated and aligned.

The machine of this invention is designed to seal the bulb at one stageof the bulbs progress on the machine and then mold the sealed part intoa neck having a. tapered or sloping bottom with due regard to theprevention of an accumulation of plastic glass at the previously sealedjoint. This eliminates the presence of internal stresses later in thecooled product.

The invention also relates to details-of construction of the sealing andmolding mechanisms which will be hereinafter more fully described andalso embodied in the claim.

The invention is illustrated in the accompanying drawings, in whichFigure 1 is a plan view of the machine showing the disposition of thesealing head and molding units. Figure 2 illustrates the bulb and stemin the three main stages of manufacture as a before sealing, b aftersealing and c after molding. Figure 3 illustrates the cam which actuatesthe molding mechanism. Figure 4 is a fragmentary elevational view,partly in section, taken at station F in Fig. 1 illustrating the moldingmechanism and the means for rotating and stopping the sealing heads.Figure 5 is another view of the molding mechanism. Figure 6 is a detailof the moldoperating mechanism. Figure 7 is a plan view of Figure 6taken on line VIIVII thereof. Figure 8 is a partially sectional view ofth molds with the bulb in position after molding. Figure 9 is a planview of the molds. Figure 10 illustrates the lower part of a bulb aftermolding with a collar ready for attachment thereto.

In the manufacture of glass bulbs, as for elec- 2 indentations in theneck of the bulb, the said lugs being subsequently squeezed into thebulb neck by the perforated rim of the screw cap.

In order to mold the bulb neck to the desired shape without using asecond machine, the sealing mechanism has been provided with a moldingmechanism which is operated directly after the sealing process iscompleted.

In its essential features, the sealing mechanism does not vary from acommercial type now in use anda brief description will suffice. Referingto the drawings it Will be seen that the machine comprises a base ll onwhich is rotatably mounted the spider I2. The spider is intermittentlyrotated by suitable indexing mechanism such as the barrel cam I3 whichperiodically engages and shifts the indexing disc M which is fixed tothe spider. The barrel cam is operated through the usual speed reductionmechanism from the motor l5. On the spider are secured the sealing rodguides It in which are sealing rods, it, which rotate in the guides. Theraising and lowering of the sealing rods is effected by the cam track itin the .base H. The glass bulb is seated on the cleats l9 carried by thecollar 23 which is supported by the stanchions 2i and rotates with theflange plate tric light or for electronic purposes it has been foundnecessary to shape the neck of the bulb after sealing to conform withthe fittings em- 22 of the sealing rod.

The rotation of the sealing rod and the glass bulb is effected by afriction cone transmission; the sealing head having a cone 23frictionally engaging the cone 24 rotative with the sprocket 25. Thesprockets 25 are driven by the sprocket chain 26 from the drivingsprocket 2'! actuated through the usual speed reduction means by themotor l5.

The glass bulbs pass through the usual processes of sealing, progressingfrom station A which is the loading station to station E where thesealing operation is completed and Where the neck of the bulb is againheated in order to render the glass sufficiently plastic for the moldingoperation, gas and air being fed to the burners 28 from the supply pipes29. I

At station F it is necessary to stop the rotation of the glass bulb inorder to permit the molding operation to be performed. This stoppage iscaused by the contact of the horizontal pin 33 fixed in the hub of thecone 23, with the fixed stop such as the pin 3i in the base. and

the cone 2d then slips on the cone 23. At the next movement of thespider the pin 30 disengagesitself from the pin 3! and the sealing headwill therefore rotate again at the next station G where there is novertical pin to stop it.

The molding mechanism which is shown as situated at station F is mountedon the standard 32 secured to the base as at 33, the standard beingprovided with the spaced horizontal brackets 34 at the top of thestandard, the mechanism for operating the mold being mounted between thebrackets. The mold comprises two halves 35 and 35 secured to thesupports 31 and 38 rotatably adjustable by the screws 39 in the moldarms 46 and 4| relatively to each other so that they will be properlyaligned when closed. Their position is thus originally fixed, and may becorrected in use to compensate for wear, by loosening the screws 39,rotating the halves 35 and 3B, and then tightening the screws.

The mold has a conical bottom 62 sloping upwardly and outwardly from thecircular aperture 14, the diameter of which exceeds that of the stem ofthe bulb so that when the two halves of the mold come together againstthe neck of the bulb the plastic glass is prevented from accumulating.at the previously sealed joint, thus eliminating internal stresses inthe bulb which would otherwise result. The lower vertical wall of themold is provided with projections or buttons i5, usually in the form ofends from the cap screws 16 which are secured by the nuts Tl in theholes 78 in the bodies of the mold. The buttons 15 make the dents 15a inthe reduced neck of the bulb which are spaced so as to register 'withthe projections 1% formed by externally denting the lugs of the screwcollar [50. This is the object of the molding operation. In order tofacilitate the retraction from the bulb neck after molding and toprovide for the withdrawal of the studs or buttons from the glasswithout marring the. indentations, the studs are slightly flat ened ontheir under sides, as will be evident from Figure 8.

The mold arms, provided with bell-crank arms 42 and 43 are mounted onthe pins 45 and d j-o'urnalled in the brackets 3d. The meshing spurgears 36 fixed on the pins 34 and t5 insure equal and smooth rotation orswinging of the mold arms. The bell cranks 42 and 43, through the togglelinks 41 and d8 pivoted to link d9 are actuated by the lever 56fulcrumed on the support 5i. The lever 59 is raised and lowered by thelift rod 52 slidable within the standard 32, the

lift rod 52 being provided with the cam roller 53 at its lower end, Fig.3, engaging the closed cam track 5 5 of the cam 55 which is rotated fromthe barrel cam shaft by the transmission means shown.

In order to insure yielding movement and contact of the mold with theplastic neck of the glass bulb, the lever 551 is provided with the pin.56 which is sliclable in the slots 51 of the furcations of bifurcatedguide bracket 58, the bracket having pivot mounting 59 on the lift rod52 whereby any binding of the lever during its arcuate travel isprevented. V 1 The stop-blocklill fixed in the bracket 58 depresses thelever on the downward stroke of the lift rod and causes the mold toopen, the arms 58 then separating and diverging as indicated by thedotted lines. On the up-stroke of the rod, causing theclcsing of themolcLthe lever 56 is raised by thesprings Bl which cause the molds toclose comparatively gently and resiliently .4 not be lifted from thecleats ill by the upward pressure exerted by the sloping or cone-shapedbottom 62 of the mold members. This is done to prevent the bulb beingmoved out of vertical alignment and also preventing the indentationsmade by the mold from being too low and thus providing an inaccuratelocation for reception of the projections on the screw collar. In orderto hold the bulb in position on the cleats the disc 63 is provided. Thedisc has a hollowed bottom in which a dished lining E4 of asbestos orsimilar material is placed, the slightly compressible material of thelining being adapted to bear down on the top of the bulb. The disc 63 ismounted on the vertical rod 65 fixed by the set-screw 66 in the carrier51 from which depends the vertically extending rack 68 meshing with therack gear 69 rotatable on the pin 44 and operated solely by the lever 70and the link 1 I. The lever lit is secured to gear 83 and hasadjustableconnection by the slotted link H with the mold operating lever50. The vertical position of the disc 68 can be regulated by adjustingthe lever it! in the slot 72 by means of the adjusting screw 13. Afterthe molding is completed the bulbs are subjected to the usual annealingprocess at station G and is then unloaded at station E.

It will be evident that a bulb may be sealed and also molded to receivethe screw collar of the attaching fixture without removing the bulb fromthe machine.

I claim: I

In a machine for molding glass bulbs, comprising a bulb support, amolding mechanism comprising a standard, bell crank arms pivoted on thestandard, a lift rod, a pivoted arm and links connecting the lift rodand the bell crank arms, molds at the ends of the bell crank arms,spring means in said machine selectively compressed and expandedresponsive to movement of said lift rod for softening the approach andthe pressure of the molds on the bulb, a disc for engaging the top ofthe bulb and slidable in the molding mechanism standard, a rack formoving the disc, a pinion in engagement with the rack, an arm for movingthe pinion, and a link connecting the pivoted arm for operating the moldbell crank arms and the arm for moving the pinion whereby the disc iscaused to engage the top of the bulb when the molds engage the bottom ofthe bulb.

. 1 CHARLES EISLER.

REFERENCES 'crrno The followingreferences are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Swedish June 21, 1934

